Ok, so let me put this all together.
I know it's engine oil because I'm always down 2 quarts within a span of 5,000km.
Yes, this issue is happening at cold starts. This morning I stood behind it, used the remote start and thick, white, blueish smoke came out for 2-3 seconds, then exhaust vapours.

the blue smoke on first starting was 100% on the chev/GM 305CU engines. the valve guides GM did not properly machine to prevent this. with a 2008 engine my guess would be a valve issue, possible seals.

if you have the AFM this may be serious . can also be the valve cover internal PCV system. may have had this fail with the use of non GM approved engine oils. sludge forms causing the crankcase venting system to not work correctly.